<!doctype html>
<html>
<head>
<meta charset="utf-8">
  <meta name="viewport" content="height=device-height, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no"/>
<title>vue.js计算器</title>

<style>
body {
  background: linear-gradient(to right, #85D8CE, #085078);
}

#app {
  font-family: 'Avenir', Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-item: center;
}

.calculator {
  width: 440px;
  padding: 20px;
  border-radius: 5px;
  margin: 20px auto;
  font-size: 16px;
  background-color: #333333;
}

.input {
  width: 420px;
  height: 50px;
  border-radius: 0px;
  border: 1px solid black;
  background-color: #333333;
  color: #d9d9d9;
  padding: 0 5px 0 5px;
  margin: 0 0px 10px 0px;
  font-size: 30px;
}

.input:focus,
.input:active {
  border-color: #03a9f4;
  box-shadow: 0 0 4px #03A9F4;
  outline: none 0;
}

.button {
  margin: 3px;
  width: 63px;
  border: 1px solid #0d0d0d;
  height: 30px;
  border-radius: 4px;
  color: #d9d9d9;
  background-color: #1a1a1a;
  cursor: pointer;
  outline: none;
}

.mode {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-evenly;
}

.equal-sign {
  background-color: green;
  width: 133px;
}

.toggle-button {
  border: none;
  background-color: #333333;
  cursor: pointer;
  outline: none;
  font-size: 1rem;
  color: #fff;
  text-shadow: -1px -1px 0 rgba(0, 0, 0, 0.35);
}

p {
  margin-top: 0;
}

button::-moz-focus-inner {
  border-color: transparent;
}
</style>
</head>
<body>

<script src="js/vue.min.js"></script>

<div id="app">
  <div class="calculator">
    <button @click="changeModeEvent" class="toggle-button">
      <p v-if="changeMode">显示高级模式     ⚈</p>
      <p v-else>显示基本模式    ⚆</p>
    </button>
    <div class="results">
      <input class="input" v-model="current" />
    </div>
    <div class="mode" v-if="changeMode">
      <button class="button" @click="press">7</button>
      <button class="button" @click="press">8</button>
      <button class="button" @click="press">9</button>
      <button class="button" @click="press">*</button>
      <button class="button" @click="press"><=</button>
      <button class="button" @click="press">C</button>
      <button class="button" @click="press">4</button>
      <button class="button" @click="press($event)">5</button>
      <button class="button" @click="press">6</button>
      <button class="button" @click="press">/</button>
      <button class="button" @click="press">(</button>
      <button class="button" @click="press">)</button>
      <button class="button" @click="press">1</button>
      <button class="button" @click="press">2</button>
      <button class="button" @click="press">3</button>
      <button class="button" @click="press">-</button>
      <button class="button" @click="press">x 2</button>
      <button class="button" @click="press">±</button>
      <button class="button" @click="press">0</button>
      <button class="button" @click="press">.</button>
      <button class="button" @click="press">%</button>
      <button class="button" @click="press">+</button>
      <button class="button equal-sign" @click="press">=</button>  
    </div>
    <div class="mode" v-else>
      <button class="button" @click="press">sin</button>
      <button class="button" @click="press">cos</button>
      <button class="button" @click="press">tan</button>
      <button class="button" @click="press">x^</button>
      <button class="button" @click="press"><=</button>
      <button class="button" @click="press">C</button>
      <button class="button" @click="press">log</button>
      <button class="button" @click="press">ln</button>
      <button class="button" @click="press">e</button>
      <button class="button" @click="press">°</button>
      <button class="button" @click="press">rad</button>
      <button class="button" @click="press">√</button>
      <button class="button" @click="press">7</button>
      <button class="button" @click="press">8   </button>
      <button class="button" @click="press">9</button>
      <button class="button" @click="press">/</button>
      <button class="button" @click="press">x 2</button>
      <button class="button" @click="press">x !</button>
      <button class="button" @click="press">4</button>
      <button class="button" @click="press">5</button>
      <button class="button" @click="press">6</button>
      <button class="button" @click="press">*</button>
      <button class="button" @click="press">(</button>
      <button class="button" @click="press">)</button>
      <button class="button" @click="press">1</button>
      <button class="button" @click="press">2</button>
      <button class="button" @click="press">3</button>
      <button class="button" @click="press">-</button>
      <button class="button" @click="press">%</button>
      <button class="button" @click="press">±</button>
      <button class="button" @click="press">0</button>
      <button class="button" @click="press">.</button>
      <button class="button" @click="press">π</button>
      <button class="button" @click="press">+</button>                    
      <button class="button equal-sign" @click="press">=</button>
    </div>
  </div>
</div>

<script>
let app = new Vue({
  el: '#app',
  data () {
    return{ 
      current: '',
      changeMode: true
    }
  },
  methods: {
    press: function (event) {
      let me = this
      let key = event.target.textContent

      if (
        key != '=' && 
        key != 'C' &&
        key != '*' &&
        key != '/' &&
        key != '√' &&
        key != "x 2" &&
        key != "%" &&
        key != "<=" && 
        key != "±" && 
        key != "sin" && 
        key != "cos" && 
        key != "tan" && 
        key != "log" && 
        key != "ln" && 
        key != "x^" && 
        key != "x !" && 
        key != "π" && 
        key != "e" && 
        key != "rad" && 
        key != "°"
      ) {
        me.current += key
        
      } else if (key === '=') {
        
        if ((me.current).indexOf('^') > -1) {
          let base = (me.current).slice(0, (me.current).indexOf('^'))
          let exponent = (me.current).slice((me.current).indexOf('^') + 1)
          me.current = eval('Math.pow(' + base + ',' + exponent + ')')
        } else {
          me.current = eval(me.current)
        }
      
      } else if (key === 'C') {
        
        me.current = ''

      } else if (key === '*') {
        
        me.current += '*'

      } else if (key === '/') {
        
        me.current += '/'

      } else if (key === '+') {
        
        me.current += '+'

      } else if (key === '-') {
        
        me.current += '-'

      } else if (key === '±') {
        
        if ((me.current).charAt(0) === '-') {
          me.current = (me.current).slice(1)
        } else {
          me.current = '-' + me.current
        }

      } else if (key === '<=') {
        
        me.current = me.current.substring(0, me.current.length - 1)

      } else if (key === '%') {
        
        me.current = me.current / 100

      } else if (key === 'π') {
        
        me.current = me.current * Math.PI

      } else if (key === 'x 2') {
        
        me.current = eval(me.current * me.current)

      } else if (key === '√') {
        
        me.current = Math.sqrt(me.current)

      } else if (key === 'sin') {
        
        me.current = Math.sin(me.current)

      } else if (key === 'cos') {
        
        me.current = Math.cos(me.current)

      } else if (key === 'tan') {
        
        me.current = Math.tan(me.current)

      } else if (key === 'log') {
        
        me.current = Math.log10(me.current)

      } else if (key === 'ln') {
        
        me.current = Math.log(me.current)

      } else if (key === 'x^') {
        
        me.current += '^'

      } else if (key === 'x !') {

        let number = 1
        if (me.current === 0) {
          me.current = '1'
        } else if (me.current < 0) {
          me.current = NaN
        } else {
          let number = 1
          for (let i = me.current; i > 0; i--) {
            number *= i
          }
          me.current = number
        }

      } else if (key === 'e') {
        
        me.current = Math.exp(me.current)

      } else if (key === 'rad') {
        
        me.current = me.current * (Math.PI / 180)

      } else if (key === '°') {

        me.current = me.current * (180 / Math.PI)

      }
    },
    changeModeEvent: function() {
      let me = this
      me.changeMode = !me.changeMode
    }
  }
})</script>

</body>
</html>
